Gauge switch



Sept. 22, 1931. P, H. HuTcHlNsoN 1,823,900

GAUGE SWITCH Filed May 24, 1930 2 Sheets-'Sheet l 2 Sheets-Sheet 2 F. H.HUTCHINSON GAUGE SWITCH Filed May 24, 1930 Sept. 22, w31.

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3U @am Patented Sept. 22, 1931 UNITED STATES PATENT OFFICE PHILIP H.HUTCHINSON, OF MONTCLAIR, NEW JERSEY, ASSIGNOR TO GENERAL MOTORSCORPORATION, OF DETROIT, MICHIGAN, A CORPORATION F DELAWARE GAUGEApplication tlled May 24,

This invention relates to gauges and comprises all the features ofnovelty herein disclosed. An object of the invention 1s to provide animproved feelcr operated gauge to complete one or more electriccontrolen'- euits at a predetermined sizeor at various nedeterminedsizes of a workpiece which is being machined. Another object is toprovide an improved gauge structure 1n which accuracy and reliability isobtained without resort to multiplying levers or other means formagnifving motions. Other objects are to provide improved gauge devicesfor operating an electric contact making member at a predetermined sizeot' a work-piece and Jfor eliminating or decreasing t-he deleteriouseffects of vibration on gauge indications or operations.

'lo these ends and to improve generally and in detail upon devices ofthis character, the invention also consists in the various mattershereinafter described and claimed. In its broader aspects, the inventionis not necessarily limited to the specific construction selected lorillustrative purposes in the accompruning drawings in which Fig. 1 is aside elevation of the gauge partly broken away and in section.

Fig. 2 is a front elevation with the cover plate removed and with someparts in section.

Fig. 3 is an elevation of the side opposite Fig. 1` parts of the gaugebeing broken away and in section.

Fig. 4 is a horizontal cross section of the upper portion of the gaugehousing.

Fig. 5 is a front view of one of the contact carrying arms.

Fig. 6 is a side view of a slide bar.

' ["ig. 'T is a plan view and Fig. 8 is a front view of a block andassociated parts of slight ly modified construction.

Fig. 9 is a plan view of the cam ot' Fig. 8.

'lhe numeral 4 indicates a. piece of work to be `ground to apredetermined size. In the present instance, the work is a hollow sleeverotatably supported in an;7 suitable way, preferably by rotating rollersindicated at G. 8 and l0, while a grinding wheel 12 is reeiproeated inthe bore and fed intermittent- SWITCH 1930. Serial No. 455,294.

ly against the bore wall. A lower diamond 14, on a bent arm 16, rides onthe work and supports the weight of the gauging devices therefrom. Thearm 16 is fastened by screws in a slot of a vertical bracket 18. Thebracket has a' cross groove or slot 20, dowel holes 22 and tapped holes24 for fastening it to a pivoted suporting arm (not shown) which acts asa guide for up and down movement of the gauge. The, bracket 18 islongitudinally slotted as at 26 and is adj ustably clamped to a gaugehousing 28 by a bolt 30. The bolt has` a head 32, a squared portion 33in the slot, a round portion in the body of the housing, and a clampingnut 34. The housing is closed by a removable 'front cover plate 36. ,Thehousing has rearwardly extending vertical ribs or guides 38 whichslidably embrace the bracket 1S. the ribs having projections 40 whichare connected by a strap 42 extending across the, back of the bracket.To adjust the housing longitudinally on the bracket 18, when theclamping nut 34 is loosened, a screw 44, having an operating crank 46 isthreaded in the upper end of the bracket. The screw traverses the slot26 and is journalled by a smooth shouldered extension 48 which rotatesin a smooth hole in the bolt and receives a retaining collar 50 at thelower end.

A bar 52 slides in the housing and its lower projecting end is split asat 54 and provided with mating recesses to grip the cylindrical shank 56of an arm 58 carrying an upper diamond 60. A clamping screw 62 passesthrough the split end ot the bar and through a groove in the shank tosecure the shank firmly. The diamond 60 rides on the inner wall of thework and is held up against it by spring pressure, the upper diamond 60and the lower diamond 14 preferably engaging opposite points in thediameter of the work to measure diameter directly. The bar 52 is guidedby walls 64 and 66 of the housing and is pulled upwardly by a coilspring 68 fastended at one end to a pin 70 in a recess 72 of the bar.and fastened at the other end to a stud 74 in the housing. The stud 74and the spring are contained in a recess 76 at t-he front of the bar.Another recess 78 is formed in the front of the bar above a lug 8O andreground away. The initial reading can be changed by nuts 96 as usual toadapt the indicator for different ranges of work, the initial spacing ofthe diamond points for the different diameters being determined by theadjustment of the gauge housing on the bracket Aby the screw 44.

An important part of the invention resides in the release of electriccontact making members at predetermined sizes. These contact makingmembers may complete electric circuits of any desired character but afrequent use is to energize solenoids such as those which controlreciprocation and dressing of the grinding wheel. For instance, it isone practice, in internal grinding, to complete an electric circuit,when a rough grinding operation is completed, for the reduction of feedfor finish grinding or the withdrawal of the grinding wheel fordressing, or both. Sometimes another circuit is completed to control anadditional dressing operation just before grinding is completed andusually a circuit is completed at the conclusion of grinding to withdrawthe grinding wheel at the exact size. In the present instance, there arethree contact making members which can be reliably actuated at anyselected sizes with the interval between them accurately and easilydeterminable. Accuracy is obtained by improved mechanism which obviatesthe necessity for `a plurality of motion multiplying levers and avoidsthe detrimental effects of vibration.

The block 82 is cut out as indicated at 98 to receive a gauge roller orhardened cylindrical plate 100 having holes 102 to receive fasteningscrews 104 entering the block. The plate projects below the block andengages a plurality of diamonds 106, each carried by a stud 108 in theupper end of a lever 110 pivoted on a pivot pin 112 supported by thehousing. Each lever has a lat- 55 eral lug or arm 114 carrying a pin 116encircled by a coil spring 118 which exerts pressure tending to swingits lever to a released osition. Each lever is split horizontally as1ndicated at 120, thereby making the lever springy as well as extensibleand contractible within the small range desired. A screw stud 122 isthreaded in each lever and has a conical portion 124 which will act asan eX- pander as the screw is sent home or will allow contraction of thelever as the screw is turned back. Each screw is readily accessiblethrough an opening in the housing by swinging back a pivoted cover piece125. The levers and their diamond points can be set initially by the aidof masters so that when the same sizes are reproduced in a productpiece, each diamond will reach the neutral or releasing position whichlies in a vertical radius of the cylindrical plate 100. This point willbe very accurately determinative due to the are approaching more andmore slowly to the horizontal. The obstruction to release of the levergradually fades to nothing and Wear is distributed. Also, when thediamond lies under the plate 100, it has a. locking eiect on the plateand sliding parts and prevents them from vibrating, by taking up themotion as fast as the work is ground. The cylindrical plate can beclamped in a reversed position by the screws 104 to distribute wear but,under some conditions, the clam ing screws may be omitted, as indicatein Figs. 7 and 8, to make the plate revoluble and thus provide a rollingslip release of the diamonds. Each lever carries a contact button 126 toengage a contact button 128 carried by a block of insulating material130 fastened to the housing. When a lever is released, it goes the wholedistance immediately and so makes a good and reliable contact withoutsparking or pitting of contact points. Each Contact button 126 may begrounded through the frame of the machine, the other contact 128 beingconnected to a suitable insulated wire leading out to the cord connector132.

The other devices in the housing have to do with the resetting of thelevers and are mounted so as not to interfere with the free movement ofthe sliding parts. An eccentric cam 140 is mounted to turn with a shaft142 having an operating handle 144 provided with a spring-pressedball-detent. 146. The cam engages a pin 148 which is freely slid- Y ablein an opening in the block 82. The opening also slidably receives theupper end of a resetting rod 152 and a coil spring 150. A collar 154 isclamped on the rod and a light coil spring 156 is interposed between thecollar and a stop block 158 which is fastened to the housing. The rodhas a head or bar 160 which is held up against the stop block by thecoil spring 156; The head or bar 160 overlies a portion of the lugs 114of all three levers and is held from turning by a stop plate 162fastened to the stop block. When not in its active position, the head orbar clears the lugs so that the levers are free to move to Contactcompleting position. The spring 156 is a weak spring just sufficient tohold the bar 160 elevated wuen the cam is in its inoperative position.The other spring 150 is then under little or no tension but, upon thedepression of the pin 148 by the cam, the spring 150 will overcome thetension of the Weak spring 156 and so cause the bar 160 to swing all ofthe levers to initial position; The spring 150 is intended to providefor a yielding or lost-motion resetting of the levers to avoid pressingthe levers forcibly against the rod 152 or its collar 154. After the camdepresses the pin 148, it engages the bar 82 and so depresses the up erdiamond 60 to allow removal of the worE-piece and insertion of a newpiece. When restored to their inactive positions, the resetting devicesdo not interfere with the sliding parts of the gauge. The spring 68exerts its pressure directly in the line o sliding and need only bestrong enough to lift the sliding parts and apply an additional lightpressure of the upper diamond against the Work. This spring has noadditional burden of releasing the contact making levers 110; thetension of the coil springs 118 tends to releasethe levers as thediamonds ride along the Asmooth and unobstructed cylindrical surface ofthe plate 100 but these springs cannot of themselves lift the slidingparts and cause a premature release of the levers.

The housing 28 acts as agauge carrier and the upper arm 58 and itsdiamond 60 act as a movable feeler controlling movement of the plate orcylinder 100 in accordance with the changing size of the work-piece. Thecylinder 100 is arranged beyond the diamond tipped ends of the levers110 and moves bodily directly away from the levers and their pivot pin112. The cylinder provides a curved surface which tapers or fades awaytransversely of its direction of movement at a point in the lineconnecting the pivot pin 112 to ,the center of curvature. The fade-outsurface acts to` arrest each spring-pressed lever until the diamondtipped end reaches a release point in said line and snaps'past in adirection substantially tangentially of the surface and transversely ofthe line of movement of the cylinder. elease of the lever is facilitatedby the smooth surface and the absence of any sharp obstruction at therelease point.

Figs. 7, 8 and 9 indicate a modified construction wherein the spring 150is omitted and the resetting rod 152a is carried entirely through theblock to engage the cam directly. The cam has a central rib 1400 whichis eccentric with respect to the shaft 142, adjacent portions 164 of thecam being concentric with the shaft for their major part but projectingto form the cam projections 166. The block is provided with a centraldepression 16S forming a lost-motion space for the eccentric rib 14011so that rotation of the cam shaft for 180 will first lower the resettingrod 152a infiependently of the block and then lower the block when thecam projections engage the top of the block at opposite sides of thedepression. In this modification, the contact carrying levers 110 areprovided with sockets 168 for stiff coil safety springs 170 engagingbars 172 carrying the diamond holding studs, the springs pressing thebars outwardly to a definite position determined by stop pins 174passing through the bars and engaging the upper walls of holes or slots176 in the levers.

I claim:

1. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a contact carrying member movably mounted on the gauge carrier, meansfor urging the member towards contact making position, a plate having acurved surface arresting the contact carrying member, and meanscontrolled by the feeler for moving the curved surface of the plate torelease the contact carrying member; substantially as described.

2. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a contact carrying member movably mounted on the gauge carrier, meansfor urgingthe member towards contact making position, a plate having acylindrical surface gradually approaching `the contact carrying member,and-means controlled by the feeler for moving the cylindrical surfacebodily alongfa radius thereof and directly away from the contactcarrying member; substantially as described.

3. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a contact carrying member movably mounted on the gauge carrier, meansfor urging the member towards contact making position, a hardened tip onthe contact carrying member, a hardened cylinder having its surfaceengaging the tip, and means controlled bythe feeler for moving thecylinder bodily away from the tip; substantially as described.

4. In a device of the character described,

, a gauge carrier, a feeler movable with respect to the carrier andengaging the work to be tested, a contact carrying lever pivotallymounted on the gaugev carrier, means for urging the contact carryinglever towards contact making position, a plate having an arrestingsurface gradually fading away transversely of the lever, and meanscontrolled by the feeler for moving the arresting surface of the. plateaway from the pivotal mounting of the lever; substantially as described.

5. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a contact carrying lever pivotally mounted on the gauge carrier, meansfor urging the contact carrying lever towards contact makinaf position,a plate having an arrestlng sur ace gradually fading away transverselyof the lever, means controlled by the eeler for moving the arrestingsurface of the plate in the direction of the length of the lever, andmeans for varying the distance between the end of the lever and itspivot; substantially as described.

6. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrierand en gagmg the work to be tested, acontact carrying member movably mounted on the gauge carrier, means forurging the member towards contact making position, a plate having acurved surface arresting the contact carrying member, a block carryingthe plate, and means for causing the block to move in unison with the`feeler to release the contact carrying member from the plate;substantially as described.

7. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a contact carrying member movably mounted on the gauge carrier, means lfor urging the member towards contact making position, a cylinder havingits surface arrestingI the contact carrying member, a block having arecess rotatablyreceiving the cylinder, and means for causing the blockto move in unison with the feeler to release the contact carrying memberfrom the cylinder; Substantially as described.

8. In a device of the character described, a gauge carrier, a eelermovable wlth respect tothe carrier and engaging the work to be tested, acontact carrying member movably mounted on the gauge carrier, means forurging the member towards contact making position, a plate having atapering surface arresting the contact carrying member, a block carryingthe plate, a bar slidable on the carrier and supporting the block,-andmeans for attaching the feeler to.the slide bar; substantially asdescribed.

9. In a device of the character dfscribed, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a contact carrying member movably mounted on the gauge carrier, meansfor urging the member towards contact making position, a plate having atapering surface arresting th'e contact carrying member, a blockcarrying the plate, a bar slidable on the carrier and supporting theblock, means for attaching the feeler to the slide bar, and a springurging the plate away from the contact carrying member and pressing thefeeler against 'the work; substantially as described.

10. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a plurality of contact carrying members movably mounted on the gaugecarrier, means for individually urging the contact .z carrying memberstowards contact making position, a plate having a tapering surfacearrestin t e contact carrying members, means or individually setting thecontact carrying members with respect to the plate, and means forcausing the late to move in unison with the eeler to re ease the contactcarrying members successively from the plate; substantially asdescribed.

l1. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a Contact carrying member movably mounted on the gauge carrier, meansvfor urging the member towards contact making position, a plate having acurved surface for arresting the contact carrying member, means formoving the plate in unison with the feeler to release the contactcarrying member, and a cam for first returning the contact carryingmember, and for thereafter returning the plate to arresting position;substantially as described.

12. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to be tested,a contact carrying member movably mounted on the gauge carrier, meansfor urging the member towards contact making position, a plate forarresting the contact carrying member, means for moving the plate'inunison with the feeler to release the contact carrying member, a cam, aspring-pressed rod actuated by the cam to return the contact carryingmember, and means subsequently actuated by the cam for returning theplate to arresting position; substantially as described. n

13. In a device of the character described, a gauge carrier, a eelermovable with respect to the carrier and engaging the work to be tested,a contact carrying member movably mounted on the gauge carrier, meansfor urging the member towards contact making position, a block havingmeans for arresting the contact carrying member, and controlled by theeeler to release the contact carrying member, a rod slidable in theblock to return the contact carrying member, and means to successivelyactuate the rod and the block; substantially as described.

14. In a device of the character described, a gauge carrier, a feelermovable with respect to the carrier and engaging the work to bel tested,a plurality ofcontact carrying members movably mounted on the gaugecarrier, means for urging the members towards contact making position, ablock having means for arresting the contact carrying members andcontrolled by the feeler to release the contact carrying members, a rodslidable in the block and having a head to return the contact carryingmembers to arrested position, and means to successively actuate the rodand the block; substantially as described.

rection of 15. In a device of the character described, a gaugecarrier,aplate movable with respect to the carrier to a position determined by adimension of the work to be tested, a contact carrying member supportedby the carrier and movable transversely tothe dimovement of the havlngan arresting surface gradually fading out in said transverse directionand engaging said contact carrying member, and means for urging saidmember-past said fadeout point when theplate reaches said ositiondetermined by the dimension o the work; substantially as described.

16. In a device of the character described,

a. gauge carrier, a plate supported by the carr1er and movable thereonto a position determined by a dimension of the work, a contact carryinglever pivoted at one of its ends to the carrier and having its other endin y engagement with the plate, the plate having a curved surface whosecenter of curvature is beyond the end of the lever, and a spring urgingthe lever in a' direction to carry its plate-engaging end towards aradius of the curved surface; substantially as K described.

17. In al device o'f the character described,

a gauge carrier, a contact carrying lever ivoted at one of its ends tothe carrier, a ate supported by the carrier and movable t er on in adirection directly away from the pivot of the lever to a positiondetermined by a dimension of the Work to'be tested, the plate having acurved surface engaging the free end of the lever and approaching moreand more slowly to a release point in the line connecting the pivot ofthe lever to the center of curvature of said surface, and a sprin urgingthe free end of the lever along sai surface towards said point ofrelease as the plate recedes from said pivot; substantially asdescribed.

- In testimony whereof I hereunto aix my slgnature. A

PHILIP H. HUTCHINSON.

plate, the plate

